[PATCH] ASoC: SOF: imx: fix reverse CONFIG_SND_SOC_SOF_OF dependency

[Arnd Bergmann]

CONFIG_SND_SOC_SOF_IMX depends on CONFIG_SND_SOC_SOF, but is in
turn referenced by the sof-of-dev driver. This creates a reverse
dependency that manifests in a link error when CONFIG_SND_SOC_SOF_OF
is built-in but CONFIG_SND_SOC_SOF_IMX=m:

sound/soc/sof/sof-of-dev.o:(.data+0x118): undefined reference to `sof_imx8_ops'

Make the latter a 'bool' symbol and change the Makefile so the imx8
driver is compiled the same way as the driver using it.

A nicer way would be to reverse the layering and move all
the imx specific bits of sof-of-dev.c into the imx driver
itself, which can then call into the common code. Doing this
would need more testing and can be done if we add another
driver like the first one.

Fixes: f4df4e4042b0 ("ASoC: SOF: imx8: Fix COMPILE_TEST error")
Fixes: 202acc565a1f ("ASoC: SOF: imx: Add i.MX8 HW support")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 sound/soc/sof/imx/Kconfig  | 2 +-
 sound/soc/sof/imx/Makefile | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/sound/soc/sof/imx/Kconfig b/sound/soc/sof/imx/Kconfig
index 5acae75f5750..a3891654a1fc 100644
--- a/sound/soc/sof/imx/Kconfig
+++ b/sound/soc/sof/imx/Kconfig
@@ -12,7 +12,7 @@ config SND_SOC_SOF_IMX_TOPLEVEL
 if SND_SOC_SOF_IMX_TOPLEVEL
 
 config SND_SOC_SOF_IMX8
-	tristate "SOF support for i.MX8"
+	bool "SOF support for i.MX8"
 	depends on IMX_SCU
 	depends on IMX_DSP
 	help
diff --git a/sound/soc/sof/imx/Makefile b/sound/soc/sof/imx/Makefile
index 6ef908e8c807..9e8f35df0ff2 100644
--- a/sound/soc/sof/imx/Makefile
+++ b/sound/soc/sof/imx/Makefile
@@ -1,4 +1,6 @@
 # SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
 snd-sof-imx8-objs := imx8.o
 
-obj-$(CONFIG_SND_SOC_SOF_IMX8) += snd-sof-imx8.o
+ifdef CONFIG_SND_SOC_SOF_IMX8
+obj-$(CONFIG_SND_SOC_SOF_OF) += snd-sof-imx8.o
+endif
-- 
2.20.0